Portable foldable electronic piano

ABSTRACT

Portable and foldable modular electronic keyboard which includes a keyboard having a plurality of white and black keys capable of reproducing the notes of a piano through an individual headphone by using associated electronics. The foldable keyboard is formed from a plurality of modules, each module having a plurality of white and black keys, and each module being joined to another module by a flexible membrane. When the modules are folded together, the keyboard has the volume of a book. When the modules are unfolded, the keyboard presents a genuine piano keyboard with seven octaves. The white keys and the black keys forming each module have a low thickness.

This invention relates to electronic devices for producing musicalsounds. More particularly, the present invention relates to a portableand foldable modular electronic piano.

BACKGROUND OF THE INVENTION

Though the world of music is full of pleasure, musicians must playregularly and assiduously. A pianist for example, even an amateur, mustpractice almost everyday in order to keep his fingers nimble and toachieve and maintain perfect control of the keyboard.

Now, whereas a harmonica player or a violinist can carry theirinstrument, a pianist faces real difficulty in transporting his piano.

Of course, electronic keyboards which are easier to carry than a pianohave appeared. However, existing models are still cumbersome, eventhough they only have a four-octave or five-octave keyboard. Forexample, German patent 9208106 discloses a keyboard capable of beingfolded in two parts, thus enabling easier transport, but the features ofthis keyboard (weight, size, operating mode) are still identical tothose of existing keyboards that typically have only five octaves.

SUMMARY OF THE INVENTION

An object of the invention is to provide an ultra-light, foldable andunfoldable piano keyboard which is easy to carry.

Another object is to provide a foldable keyboard having the 7 octaves ofa genuine piano keyboard.

Yet another object is to provide a portable keyboard whose size, oncefolded, is not higher than that of a book and, once unfolded, provideseveryone an inexpensive means to practice with an instrument whose toneis similar to that of a real piano.

An advantage of the present invention is that it permits easy practiceat all times because, once unfolded, the keyboard is similar to a realpiano keyboard.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a keyboard ready for operation.

FIG. 2 shows an exploded view of the keyboard showing 4 modules tohighlight the flexible membrane that makes them interdependent andappears when the keyboard is subjected to a traction force.

FIG. 3 is a cross-sectional view of the keyboard that shows one possiblefolding mode.

FIG. 4 shows the keyboard being folded according to a different foldingmode.

FIG. 5 shows a simplified view of the folded keyboard.

FIG. 6 illustrates the keyboard in a wound rather than folded mode.

FIG. 7 depicts an embodiment of the keyboard having an elastic foamwhich urges the keys of the keyboard back to their open position.

FIG. 8 illustrates an embodiment of the keyboard having a piezoelectriccontact located under a key.

FIG. 9 illustrates an embodiment of the keyboard having three contactslocated under a key for providing three possible sound levels.

FIG. 10 illustrates the flexible membrane which joins the modules of theelectronic keyboard together.

FIG. 11 shows a circuit for operation of the electronic keyboard of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, the keyboard comprises white keys (1) and black keys(2) for semitones like real pianos. As illustrated by FIGS. 2 and 10,the keyboard consists of four modules (9) made interdependent upon eachother by a flexible membrane (34) made of materials such as rubber,latex or plastic, that can mechanically withstand the strains producedby folding/unfolding operations. In one embodiment, modules (9) aresolid and reproduce the white keys (1) and the black keys (2) through aslight raised pattern. According to another embodiment of the invention,the modules (9) forming the keyboard are made of independent mechanicalkeys spaced from one another by a gap that helps separate them, like areal piano keyboard.

In order to reduce overall dimensions and weight, the white keys (1) andthe black keys (2) that make up each module (9) have a low thickness butform a true piano keyboard. The semitone black keys (2) are alsoembossed for proper ergonomics.

Of course, each key will match a piano sound, which can either bedigitized from a real piano sound and stored in an appropriate memory,or played by a synthesizer. When these keys are hit, a piano sound willbe reproduced through individual earphones. The depression of the keysrequired to trigger the sound generator may be calibrated so that merelyplacing a finger on the keyboard does not produce any sound. Instead, apiano sound will be reproduced only when the keyboard keys (1) and (2)are hit.

Under each key there is one or several contacts: a single contact for asingle sound level (all or nothing), two contacts for two possible soundlevels, three or more contacts for three sound levels or more, asillustrated in FIG. 9. The contacts can be lined up with the verticalaxis or be arranged along a template (15). As depicted in FIGS. 7 and 9,an elastic foam (16) or a spring (18) are used to push back the keys.

The contacts can be made with ink (inexpensive), capacitive, resistive,or better piezoelectric (33) technology, as shown in FIG. 8. In thatcase, the variable mechanical energy of the hit creates a correlativecurrent capable of generating a plurality of nuances. The whole set ofcontacts is connected to an electronic unit having a sound synthesizer.

Each contact creates a signal and each signal is sent through anelectrical wire. As illustrated in FIG. 11, all these wires are linkedto a flexible strip (21) connected to a hardwired logic circuit (22)controlled by a microprocessor (23). The number of wires contained insaid strip can be limited to reduce wiring costs. Electrical power maybe supplied by means of standard or storage batteries (24), or by themains through an A/C adapter.

In one embodiment, the piano sounds played when hitting keys (1) and (2)are digitized sounds from a real piano, stored within memory (25). Thus,microprocessor (23) controls a memory package (25) comprising ROM memoryto store permanent data, like piano digitized sounds, and RAM memorythat stores, for instance, the records of music sections just played. Itis to be noted that specific circuits integrating the whole electronicsset forth can be found, including 32-channel polyphonic microprocessors.

According to another embodiment, piano sound signals are produced by asynthesizer (30). The piano sound signals are then amplified by means ofa preamplifier (31) and distributed to two headphones outputs (3). In aspecific version of this embodiment, synthesizer (30) can be designed soas to reproduce the tones of several instruments.

The electric keyboard of the present invention typically has neitherspeakers nor sound amplifier circuits in order to reduce its overalldimensions and weight. The provision of two headphones sockets willenable a trainee and a teacher to listen at the same time.

A right/left stereo effect is achieved by means of two progressive rampfilters (32). One filter softens the treble for the left channel, thusgiving priority to the bass, the other one, on the contrary, reduces thebass, thus giving priority to the treble for the right channel. Thissimple and inexpensive device helps produce the spatial sound effect ofa piano.

A pedal socket (5) may be used to connect a pair of pedals (6) to theelectronic keyboard. The effect of pedal operation is rendered throughaction on the preamplifier, the right pedal being used to extend a soundand the left pedal being used to soften it.

The electronic keyboard of the present invention may include aninterface (26) for external memory devices such as disks (27),microcassettes (28) or plug-in memory modules (29), as illustrated inFIG. 11. These devices can be purchased later and can store scores, apiano training method, etc.

As shown in FIG. 1, another embodiment of the invention can integrate ascreen (8) for displaying useful information to the user, such as thescrolling of a score. As shown in FIG. 11, screen (8) is controlled bymicroprocessor (23) and is connected to memory (25) and to hardwiredlogic circuit (22), so that the whole data can be stored either into thememory (25), or into external memory devices (27), (28), (29).

FIG. 1 also illustrates that the electronic keyboard can also beprovided with LEDs (7) that light up as needed, for example to tell themusician what key is to be pressed. The whole set of LEDs (7) iscontrolled by the hardwired logic circuit (22) and the control signalsof said LEDs are sent through the flexible strip (21) that integratesthe wires. See FIG. 11.

The invention can also be provided with an output for connecting anamplifier or a hi-fi system, and with a MIDI output for connecting theinvention to a computer.

According to another embodiment of the invention, a female socket (19)can receive acoustical signals from a personal stereo (20), an extensioncord linking the personal stereo headphones output to the socket (19),said signals being managed by the preamplifier (31) and mixed with thepiano sound signals to be sent to headphones (4). See FIG. 11. Thisembodiment is useful for a training method.

According to another embodiment, the keyboard is fully flexible andpermits easy folding with no joint. It is even better when theelectronic keyboard can be wound upon itself, as illustrated by FIG. 6.Flexible circuits have been developed which enable such an embodiment.

The integration and the association of the various items that make upthe invention enable to offer both the general public and the musician anew portable and original means for initiating and training oneself atlow cost without bothering the neighbors.

The small size and low weight of the keyboard make it a true portableinstrument that can be taken systematically by the pianist into his orher satchel for regular practice.

Another significant advantage of the electronic keyboard of the presentinvention is that, through the use of headphones, it does not produceany noise likely to bother the neighbors while enabling the pianist tocontinue practicing, even when on the move.

The shapes, dimensions and arrangement of the various items, as well asmaterials used for the manufacturing, such as hardened paper, cardboard,plastic, composite materials, etc., may vary without departing from thespirit of the invention set forth above.

What is claimed is:
 1. A portable, foldable modular electronic piano,comprising i) a device for generating electrical signals correspondingto the notes of a piano, which device includes a preamplifier; ii) aplurality of modules, with each module comprising a plurality of whitekeys and black keys operatively connected to said device; and iii) atleast one flexible membrane which joins the modules together, whereinthe membrane is sufficiently flexible to permit the modules to be foldedover one another when not in use, and unfolded when the keyboard is tobe used, such that when unfolded, the plurality of modules simulates apiano keyboard having seven octaves, iv) a plurality of contactsoperatively connected to and located under each key so as to permitselection of a particular sound level from a number of sound levelscorresponding to the number of said contacts, wherein said contactscomprise piezoelectric contacts which generate a current correspondingto an amount of mechanical energy exerted upon a corresponding key, andwherein said device is contained within said plurality of modules. 2.The electronic piano of claim 1, wherein said keys of each modulecomprise a slight raised pattern, with said black keys being embossed.3. The electronic piano of claim 1, wherein each key is spaced from theother keys by a slot.
 4. The electronic piano of claim 1, wherein saidplurality of contacts are arranged along a template.
 5. The electronicpiano of claim 1, wherein said device further comprises a memory, andsaid notes of a piano comprise digitized sounds from a real piano whichare stored into said memory.
 6. The electronic piano of claim 1, whereinsaid device further comprises two headphones sockets operativelyconnected to said preamplifier.
 7. The electronic piano of claim 6,further comprising two progressive ramp filters operatively locatedbetween said headphones sockets and said preamplifier, wherein onefilter softens the treble for a left channel, thus giving priority tothe bass, and the other one, on the contrary, reduces the bass, thusgiving priority to the treble for a right channel, so as to be capableof producing a stereo effect.
 8. The electronic piano of claim 7,wherein said device further comprises an interface for at least oneexternal memory device selected from the group consisting of disks,microcassettes or plug-in memory modules.
 9. The electronic piano ofclaim 1, further comprising a screen for displaying data as it is beingstored by said keyboard or by external memory devices operativelyconnected thereto.
 10. The electronic piano of claim 1, furthercomprising a plurality of LEDs located on at least one of said modulesfor displaying information.
 11. The electronic piano of claim 1, whereinsaid keyboard can be wound upon itself to form a cylinder.
 12. Theelectronic piano of claim 1, further comprising a female socket adaptedto receive signals from a personal stereo through an extension cordlinking a stereo headphone output from said personal stereo to saidsocket, said socket being operatively connected to said preamplifiersuch that said signals from said personal stereo can be mixed withsounds generated by the keyboard.